Typewriter ribbon spool cover



March 10, 1970 s, D, CAPPOTTO 3,499,517

TYPEWRITER RIBBON SPOOL COVER Filed June 26, 1967 2 Sheets-Sheet 1 INVEN TOR. SAMUEL D. CAPPOTTO will AGENT s. D. CAPPOTTO TYPEWRITERRIBBON SPOOL covsa March 10, 1970 2 Sheets-Sheet 2 Filed June 26, 1967 INVENTOR SAMUEL D. CAPPOTTO A G E NT United States Patent 3,499,517 TYPEWRITER RIBBON SPOOL COVER Samuel D. Cappotto, Syracuse, N.Y., assignor to SCM Corporation, a corporation of New York Filed June 26, 1967, Ser. No. 648,912 Int. Cl. B41j 29/02 US. Cl. 197-186 2 Claims ABSTRACT OF THE DISCLOSURE A linkage mechanism for guiding and positioning a typewriter ribon-spool cover to open or closed positions. The mechanism includes a pair of hinges having a pair of spring biased links pivotally connected between the cover and the machine frame which first guides the cover through a tilted path and then through a rearward swinging path to provide maximum access to the machine ribbon carrier.

BACKGROUND OF THE INVENTION This invention relates to ribbon spoo'l covers for typewriters or like machines and more particularly to the hinging means used for raising the cover to provide access to the machine ribbon carrier.

Most ribbon spool covers are simply pivoted at their rearward end so the cover front may be raised and tipped back. This type of cover does not provide enough access to the machine ribbon carrier for installing the ribbon from one of todays popular ribbon cartridges. These cartridges must be manipulated quite close to the carrier to effect an efficient ribbon installation.

The closest known prior art is disclosed in Patent No. 3,135,372 issued to K. T. Baughman on June 2, 1964. The Baughman structure does provide sufiicient access to the ribbon carrier when the cover is open for effecting a cartridge type ribbon installation. However, the critical arrangement of the parts employed to guide the cover when it is being raised or lowered could present a disadvantage during operation.

More specifically, the two guide means for the arcuate cover arms each are comprised of four studs and a plate. These studs are positioned so as to straddle its co-operating sheet metal arcuate arm, with each of two pairs of studs contacting opposite edges of the arm. This type of guide is critical in that its relability and operational ease is strictly dependent upon the trueness in shape of the arcuate arms. If this trueness is slightly altered in any way, such as from an accidental bump against the opened cover, the arms would bind within their guides thereby producing a cover that is hard if not impossible to operate.

SUMMARY OF THE INVENTION The invention overcomes the above mentioned disadvantage of the Baughman structure in that it is sturdy but yet flexible enough to withstand accidental abuse.

The object of this invention is to provide a ribbon spool cover hinge mechanism which first guides the cover through a tilted path and then through a rearward swinging path to provide maximum access to the machine ribbon carrier.

Another object of the invention is to provide a hinge mechanism of the type described that is biased toward the open position when the cover is raised and biased toward the closed position when the cover is lowered.

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BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a left side elevational view of a typewriter showing orientation of the ribbon spool cover therewith;

FIGURE 2 is a left side sectional view on an enlarged scale showing the left cover linkage in its rest position, the linkage being one of two such linkages, each of which is disposed at its respective side of the cover;

FIGURE 3 is a left side sectional view showing the hinge means at the end of the tilted path portion of the cover opening movement; and

FIGURE 4 is a view similar to FIGURE 3 but showing the hinge means at the end of the swinging path portion of the cover opening movement.

DESCRIPTION OF THE PREFERRED EMBODIMENT In general the novel hinge mechanism is comprised of a four bar linkage at each end of the ribbon cover having two long links, each of which are connected between two shorter links. One of the short links is rigidly mounted to the cover while the other short link is rigidly mounted to the machine side frame. The linkage also employs a tension spring which is connected at its ends to the two shorter links.

More specifically and with reference to FIGURE 2, the cover 10 is rigidly mounted by screw 12 to the front short link 14 which in turn has a lift link 16 and a pivot link 18 both of which are pivotally mounted to opposite sides of the lower extension of link 14 by screws 20 and 22 respectively. The lift link 16 and the pivot link 18 are both pivotally mounted at their other ends to the other short link 24 by screws 26 and 28 respectively. Short link 24 is rigidly mounted on a frame member 29 by screws 31. A spring 30 is connected between links 14 at spring anchor 33 and 24 at screw 26, and biases the cover 10 downward in its closed or rest position with a forked lip 32 of link 14 limiting against frame member 29. An elongated pivot aperture 36 is provided in pivot link 16 for allowing the linkage to exceed its limit and provide for smooth operation. The linkage exceeds this limit during two portions of its operation, once when it is initially lifted and again as it nears the fully open position, whereupon, in both instances the lift link 1-6 oscillates with respect to its pivot screw 26 by utilizing the space provided by the aperture 36.

To move the cover 10' from the closed position of FIGURE 2 to the open position of FIGURE 4, the cover 10 is lifted in the direction of the arrow in FIGURE 2. The cover 10 then tilts forward as it is raised and just before it assumes the position shown in FIGURE 3, the spring 30 moves across the center of screw 22 due to screw 22 pivoting about the fixed axis of screw 28 a greater amount than spring 30 pivots about screw 26 and thereby biases the cover 10 to a substantially vertical position. This movement is terminated by the edge 38 of pivot link 18 abutting the threaded end of screw 20 which extends just beyond the inside surface of the lower extension of link 14. The cover 10 is then swung back with the links 16 and 18 pivoting about their respective pivot screws 26 and 28 in the rear short link 24 to the position shown in FIGURE 4. During such movement the lift link 16 oscillates as previously described to allow the linkage to exceed its limit as spring 30 now moves across the center of pivot screw 28 and biases the linkage counter-clockwise about link 24 until formed ear 40 of pivot link 18 abuts a projection 42 of lift link 16.

To restore the cover to its closed position, the cover 10 is first swung from the position of FIGURE 4 to the position of FIGURE 3. The cover 10 is then tilted backward and simultaneously lowered until assuming the position of FIGURE 2.

It can now be seen that the machine ribbon carrier 44, commonly known as a ribbon vibrator, which is adjacent the platen 46 is sufficiently accessible to permit convenient installation of a ribbon 50 using any type of existing ribbon cartridges. It is also evident that the open position of the cover 10 as shown by FIGURE 4 provides maximum accessibility to a pair of ribbon spools 48, only one shown in FIGURE 1, as they are normally supported in a machine. The ribbon spools supply a ribbon 50 to the ribbon carrier 44. It is further evident that the present invention provides a sturdy yet easy to operate mechanism while accomplishing this result.

What is claimed and desired to be secured by Letters Patent is:

1. In a typewriter or the like having a frame, a ribbon carrier supported on the frame for guiding a ribbon at a printing point adjacent a platen, a ribbon spool supported on the frame for supplying ribbon to the ribbon carrier, a cover for the ribbon spool and a hinging mechanism connecting the cover to the frame comprising:

a lift link pivotally connected at one end to the frame and at the other end to the cover and operable to raise the cover relative to the frame;

a pivot link pivotally connected at one end to the frame and at the other end to the cover and operable to tilt the cover in a direction having the underside of the cover facing toward the platen simultaneously as said lift link raises the cover;

an abutment rigidly supported on the cover and located to be contacted by said pivot link to terminate the pivoting and tilting movement of the cover from the closed position to a first open position having the cover positioned substantially perpendicular relative to the closed position;

abutment means carried by said lift link and said pivot link for engagement therebetween to terminate the movement of the cover from said first open position to a second open position having the cover above the platen with the underside thereof facing toward the platen; and

a spring having one end connected to the frame and the other end connected to the cover at a spring anchor located on one side of the pivot link pivot on the cover to bias the cover in the closed position, said spring anchor being carried by the cover to the opposite side of the pivot link from said one side as the cover approaches said first open position causing said spring to bias the cover in said first open position, and said spring anchor being carried by the cover to remain on said opposite side of the pivot link pivot as the cover moves to said second open position to bias the cover in said second open position.

2. In a typewriter having a frame, a ribbon carrier supported on the frame for guiding a ribbon at a printing point adjacent a platen, a ribbon spool supported on the frame for supplying ribbon to the ribbon carrier, a cover for the ribbon spool and a hinging mechanism connecting the cover to the frame comprising:

a lift link pivotally connected at one end to the frame located near the rearward portion of the cover adjacent the platen and at the other end to the cover located near the forward portion of the cover relative to the platen when the cover is in a closed position, said lift link being operable to move said forward portion of the cover to a position above the platen;

a pivot link pivotally connected at one end to the frame and at the other end to the cover and operable to tilt the cover in a direction having the underside of the cover facing toward the platen simultaneously as said lift link moves the cover to the position above the platen; and

abutment means carried by said lift link and said pivot link to terminate the movement of said lift link and said pivot link to locate the cover in the position above the platen.

References Cited UNITED STATES PATENTS 2,344,118 3/ 1944 Wunderlich 197186 3,123,196 3/1964 Paone et a1 197186 3,191,742 6/ 1965 Harmon 197186 FOREIGN PATENTS 1,418,745 10/1965 France.

ERNEST T. WRIGHT, JR., Primary Examiner 

